SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71a4f9359dbf2f343523b796ac0e347437913552eaf9535ec8d165b14df52512' 
  AND token = 'oC2vP+Db3hUIVL1ZQOpbHMMHdEa54fbj+A1Yuc6jx9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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