SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dbf637c9de2a88080f9cf0a099d50445ea3cdbcf9cd89773247eb3210737cec' 
  AND token = 'IhadCfKx2xIKKRgyJjvOChVOvw6QoLtkiZPV8u+37m8=' 
  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"
    }
  }
}