SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50701a708a2a1fd427352eb9fa49446c932cb72143620e6ccbefe800d8646c16' 
  AND token = 'oocGRV6THTx9+QN/cPi60ia8MUfGmS+CWl2cirvj+aA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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