SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'acfbd3159726959316bbc92f711cf80c3f67d3cd81e2134e35ea7416fbd7a90f' 
  AND token = 'GFUry7Fm4Ncj5bh2HkU3bCX0Vj6PQPUjGy8ELFRIRSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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