SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91014b5d07a382d442b683ba8d19538d49ad0e417676ef5137c3166a42430dd3' 
  AND token = '3O+OG4jzFVxjVo2gbU+vCIXbnMPTGY4diJtSfY2Xris=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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