SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e043abe49586d87a28b9dbd2ba848645293c79fcbccb84768f71044ad3afb84' 
  AND token = 'iRHKnpO5sM7ulgmgj9NE9DLXpRpKPkEAEbal0cf5DyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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