SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef795092d25938e998a1e67647deddd59a774a7055294ef1e314c2a45195525d' 
  AND token = '7PJOTKvz1WZ6C9GSBSlt3xuVLoD+1//ak6rCzX93SBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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