SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e52f09019d2b9945fe11bda1017ce8c2bd02728fe02933b8efd8faea9025511a' 
  AND token = 'IhaCQOusOOxwcUgf0i/bOxJCKk2N/5X3Osx4TVT3zrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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