SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b17eeaa135fe5342272b32fdf4f4b2ca1859c890cd20b9cb0d719ea10f51f54a' 
  AND token = 'wCVx2+7oc5v6bgSJ4+Q9RJlYFMOYrWYfwdIn1FkADyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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