SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87b3a81ee149d53cc0c6122866d0dbd6be00049c1b5ac24fa5f40adf0efbfaa1' 
  AND token = 'KjWCp+zgJGj9KUZ9kvGhnXIoVT89pjZE6Vq/weu+W+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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