SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e8f195629b156d44db22460bc3e98ae4283506ab3dae8b98f84b4f2d5f7e293' 
  AND token = 'tL4jYkzWuu5SmIoFA6NgFtBivsQOArN2moBIOjQ6NYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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