SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a91682f15fadc8e3ea9c0736c55a3f912fe34678f14c17f16c4ca7d6bf1b366' 
  AND token = 'eGLvZ0FUYmhbsvwzAYijL661heqH6vjK2fQxF4ISzg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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