SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd93b8977f8879efb40aab24bd0cba6afeb068635850bb811dfcf67f1675cee4' 
  AND token = 'qbb8WJEtfRYaqEFupoR/E8tv3vV3st2nLX8LJgI0qfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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