SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff6fd3e0cee20355b32b07aec4bf17222b67dd192ebdb3f5137af8aaf0dfd75f' 
  AND token = 'G4WFln2Tz0Z3yhMnWZ54iYqe6SD1uN2EfoORkbbEkXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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