SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09fba7d3810e93b08340b860efd4117f4be5b2b5785d3c0f2dae961471650dc6' 
  AND token = 'FnBsTNnehHh0el6+K9AQoBQ/CYvtC8UKLwVZfhDKGOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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