SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '15856d61d400df77b7e7ab9b8974cac0dc76b794df9152f6e06285b1d9833abe' 
  AND token = '6w7Ea7U2bPqS0WLChvBvRJY5eMsXRn/RXi6nVD7YQBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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