SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dc871757e715bef75bea4730b657d7d7de11835c8de83015f3fbaca6840677d' 
  AND token = 'zhqvnPh7/aQJfclwAl1FISlXV3Tuuzw1mhqc+Hy2dyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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