SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee9d0060a60a144d7ba349a1137d2689444b3350f906611fc41493f3892555b4' 
  AND token = 'WoMlmnHRvpfn2DJMfSeo8P/+ACQPIR65bRiEIQ4Zc10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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