SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '573f57a40a884dc9f95b3a0a649713f3884bc990730ba2e5ea2d352744d83326' 
  AND token = 'gJNtlyRYh8OkdBqXFC6BvUlJLjxJzyvEmGviKOIVWgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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