SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7694d1e87eeb3a1ef5b5fc50a4ee1e16a8314bc38c455f08a89eeab4e6310842' 
  AND token = 'C3vLk/cw7/5B1JF2h4TtjqMEcRn2KIoGIOVNKpNCHZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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