SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1ec11199afa1906ddbb16d2a028d8262e287d7cb324a5fe2d73f72fd36101311' 
  AND token = '2Bkh9MTOtqcZe8IfrEZS1+GoBIGA4FHYYlbT5mVNWM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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