SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fab250e845fdf44044293f64627ad9929cf6f5b307b4265af793ce5aa56a377f' 
  AND token = 'Xa4CK4GZLChqIRk9Yl3RGtr8qJKVo0ThH72WZ/I7UyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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