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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1f7a6fc5540d18c1e523750683fe849cab7ee03a5d1eede113c17f7d4181dd4' 
  AND token = 'BhRdr7bBxrb2p/a+zvQNdAWEvhcwLvqlnw+w9jIJz1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}