SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cba377636fd3c5176218a3d980dbd2b11a55dafe28ea701af7056f0b41469f95' 
  AND token = 'DXkKzGw8MgaS91LieCzbTKioKrnvxSR6JwIttS0sTBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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