SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dd690e8e8fdff4ba9da883edc57850b9b243d569dbbd8112771d0778520369b' 
  AND token = 'guPSFeOtR4HwvwjGKaVvY9vRa3wld4+YMEpCnp+mqP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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