SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd8a66b4afc13789f774b98041090b105a8ef5391fc19b82de8c19b031acce072' 
  AND token = '/M2KYv/+UlsbloX6ZOcP+FWxbQLZzFmgP5WwVQLI3Ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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