SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccd559693557bb715dce8f33ce8ec6d664ea54a865f107b25128d336174d2e9a' 
  AND token = 'D0r6qGZ/zlQ7YDwlsAh4+6Vb/OM8UliVCfzRWNoxG9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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