SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '199646f67a5366f8a06f46f2a99060c7543f9a8522f0889abdd82b602c65c939' 
  AND token = 'cdJFPNKtsJUw22NCFKq1TClJKhvb5EImflD33YFCtOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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