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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56829ba6fd6f87cd88e853f3ce91256a6d227357d1f6f3a91f2d5d720e0c6f1a' 
  AND token = 'Jh7jE3Snz9Vrqe/IyDRKbllf1RPNbc5mkiyI5WY5tpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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