SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbe1912d4fb0f8b5045e585c87d57530c950af370fac7300722ee0bf917e52d3' 
  AND token = 'pVSLLfwHtj9J2MLz+wogGRzyfqZfsFM0RCbIeBlM62Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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