SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '722500c83a361e6ddfd2cdc667ab4f354cb181e6ab982672b19ea04a9f7d6304' 
  AND token = 'MGQmtO9j0/PQN+33ZwQNTNnIrAnNwaxdFq5ypxw/4CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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