SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6d05338fe437313e4d17a077a5ec028c390b5fd5a980a9166f8de83a6fce3a57' 
  AND token = 'R/YFAsS3ZKgHVV8ibYY9Rjsmv25T6Ja/EJEW5fro+8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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