SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42b6c7f424993e13136e5dd5e325aae2f75af9e5bd26d264488a309c82ecb44f' 
  AND token = 'QCj8YxhwEwDBlakr1CjYht7PjH+Iho1df9xVpbmV/t8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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