SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dc88dd6777ba977755074a1d9821442f0386638100e5898fe94380433b2feef' 
  AND token = 'IB/xaAUUuDQPSKQtCJVMXDAO1xZN7mPtgmFZ2GzetBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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