SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ea1e6e8228a88888e9598121863d19bb436fb5754f5e68fbd9580d47a393ffc' 
  AND token = 'QXHCg9vdugzhIM2U78m1qrJjXtVRaoSTYmCyYcYq6Fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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