SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3682c64fb7b5771b9bc2f59be0083b07cdb3c0dca1db675726132236c3a80821' 
  AND token = 'YcbEcUBpzsT0VY1PLNs2R355gthGHMmMeFP+vgsc09Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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