SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c627833a8410ae974e9e6ac61f40580b2394dad27c58ea920885e87db44c933b' 
  AND token = 'yiWepQLNftvRS6ApbTJxOABsoeJpPA5LjrJ8GH2iU9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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