SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'de06744678146e00eb0e68cf7b7e5e8d6c4d959f648c45288b4fe274d3421ab3' 
  AND token = 'gFYqzy+q9j7YCXeecriMGDlf29F/NOYcGP7VOfkAwGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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