SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce3b93cd2611cc274695bf445d67bcea753ec38b2981ff08b242a8fae0549138' 
  AND token = 'dDuDGA8lvHkgANotU+U+k8YFOdKRNqtXeTy1Zq+zXmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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