SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb706e85f88dbc9f9b2e1023c5c5f3f1f5a788b73aac88176576014fcd8bf119' 
  AND token = 'IM72FbNUXQl+dmZ06wRGlankM2vVlwlpWgVHLfkZc8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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