SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2b888ac4cf34bfa18a53db9aa83549692ef31ca655f3c5dcaf2af7339a9dccad' 
  AND token = 'ZCtzuCSwZCivfuyAsu4OUU1DP+qiUGsbZZnyet1u6Vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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