SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '23b9582447f86120f7a0147785a97d4e8eaadd048cc060f7e7d5d0bae16964ab' 
  AND token = 'd0q+8v/9uExabOJyyLFKz3hOGhoJc5P8aVe965NvBUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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