SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0fc0c4ae51f051db059c27140796b54a49fe2fb537447c6e76346512fbda7be0' 
  AND token = 'H/lmzyJgrSgI86DBTAuvzDGRpxsICmQzm+EcljqJEwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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