SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b24f2956a3827a908a411b4bccd7e79da64ea8db23350e3cbe232fba6e635cef' 
  AND token = 'weDln0wOuvkdKfSYB5zUHbjyk2FJSm+bCoy3c4GZu1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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