SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7cae1621b587038cd1848565474ff485c900aceafc773521254ecb907ce86232' 
  AND token = 's1BQeGcQjidk2ZJH2vI5LjD60uE24wZlbEfAutNh2S8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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