SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5a0162ea6e7da16310557ba6c2bcdd0f268c7c14923ce3631291e64b0537798' 
  AND token = 'wPwXavUyStTPD9lwunLsYD+BsduF4obVpT+QAN8VeC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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