SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cefd384ae1f7e6421e27c92e93873f07b2bcc9bf4c76bbf6566772eede991faa' 
  AND token = '1+szkLvsv5fMiuKvwttSylwqSodSgyifgBBkqzjv1fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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