SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0b43fe96030903642148bc6f471e8e81c630f237d23d2d1404700915c082c6e' 
  AND token = 'BMuZasH4yaMZS5ulYS3oTu8o8EkvatV8MDHJz+0YRwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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