SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ca18ff01efd7f80019359a21197bc50b3eaccc3856de4a46af73737ade2f22b' 
  AND token = 'qUCw/pYZeLIh3iRhFJoomiWZp1Mz3q4NFxwj5gDKHaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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