SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd63e74273f375ee8d245e32e2c52d65d1a6b4a9cfe47b23aa1968a13cf535835' 
  AND token = 'tnMPhXu3zQBSywQTHEL/WB8+HeXgxP+Olz/WKnwHNCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}