SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f27e18d7f5502dc8c8d4ebab800a6dac797eed7cd04db97b7dab446af172408' 
  AND token = 'dYaBocck/sFd/+nHQxgRcGu5+UaQPleZGOtqHA6xbtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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