SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '903ed6ef1b917a21fa809b59e555291266e620d22979f81cfe78b96f4d743449' 
  AND token = 'H5yzn9KrkpPkZ+bRxyvAlaMACxlRi494gZJj0nfsm1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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