SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '501299e06eb1f25d493370ab37c7baca8765530edd1f5f352ca18856e68ff5b9' 
  AND token = 'uOGu38Rlv2ce8voR0nzyHHxKlI+D00xV/gVdPR66LoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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