SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1b92c265c891cc59279dcbc4690b82795c9143f472aa116b0427c075361f3fb' 
  AND token = 'TtSFvha5vfUeAJ77BHUFomupv/uLxkfCkRftkmETLt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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