SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc47dacef2063eb3854652b84389bd7eae35f8915bb52baef7654c0712db32b5' 
  AND token = 'fzKgdasYySqO6812XACAbFFRbLz/+MvwOGvtuwvmF7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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