SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '911847385cb254d93cd48939bcf50f8feecae01d1bd5bba6691d79b7d528d7fe' 
  AND token = '30tHAj7WFwuDKhpModtF4vyQRAJdk1pmJrUU7XQjmSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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