SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aac1138cf182e264e3c605e96843353c0681890b671a660ed7135d1f686e802f' 
  AND token = 'qPB62gtJl6zj1oULJk1CFZHOXIQuLcvp6kNEZOH1128=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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