SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7b06b70086392784f7577d4536571214bc2aeba3d594eb6e4d39d91abe87354' 
  AND token = 'aVvlSMffBdd8MrnycW2sCe3iRABzu6AyKQMqZwxXRxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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