SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a3dc5a7519d0cda75a228ccfdf460c2cd184b03720117928000978ace2bd9572' 
  AND token = 'F3xubVEATItvMKIWOYM+xDcfxKduiMgDcFCh6QP0W1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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