SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '488ee28d41df422734b9493a43da9678b285f37ed0f7acea0e87414e9332ee7e' 
  AND token = 'VO45jqBBa9wXjGClKA5LXR/eAteBSxfkRZS9plo0zAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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