SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7a2794dd78f7dab2490eb9b9ca621d0bc46cf8722881035fdf757525d659f7a7' 
  AND token = 'GByMeIvd1HOdyx79WrHvdOY691Z095UKb4O1IKQSfAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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