SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '690d1e87c7e2477432565b24ac7851196bfaacf80609866a0a9921cabc51c2e7' 
  AND token = 'oL8LHpw6MJ2Y8YyxpWNATZY9ag1zXg4bItfEj6+6Bsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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