SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aab865e1c1c8dbe2629b79a1654f4e05d6d927c2b313a80e2a9ee96b24e65ff0' 
  AND token = '0z7oGRBB+vTKvhmLFm7+As+sa/NfSHYOu4Epj/pAze8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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