SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a385a66ccebe7f88d0dba6d57e76792fee838e64fa233dfcb0715ecfdef934ef' 
  AND token = 'hMMuQigNc2qANM6eIWhMlKVN8/VIcp1PgKQgDcqWrhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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