SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2141b970fd75450a40114aa70a57da20d7830237d476de513f29315ce4840a60' 
  AND token = 'GeM8gXsNYrKGMHmea8/CDZZbhM1uIGL5u1Wl+veQCX4=' 
  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"
    }
  }
}