SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86522db0a14df09807bd68eba8f7358d952fba12963e838dd6df02b340fe9d1c' 
  AND token = 'SPlCTYqux+EEr3W8Uho7KOusn9sQ5IJJhKtJvoAhejo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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