SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd248c8feb0a5b8147fc7fbc95f127c098fc0da306a0feaf15ab944ebd7dab8e8' 
  AND token = 'rdjeOvy3LhrPBaUsxiJks7Y57xxWBwNRBeKA7/zbskI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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