SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1478c773abc457f5576dab5de6da76370d73ec79d49ca8b263ecfafdc1b6b989' 
  AND token = 'SfB3VFYMXSsNkO4Hz80T/v1jInNUFk4ywyEB38ZuJgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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