SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef164db40ca8546e2c6d91ac3d911efae398883a869ea586f59fc6436b25116b' 
  AND token = 'WrcH1/l6vKjkcLnShs3JeitDgZy7PVwyvw8RRa097b8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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