SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '309a701c3836a3b8dc645498db8f828fb0c7c4c2ad45ec9e967dec65f6c60cd3' 
  AND token = 'IKwjMBd5EMICV/6VXQdnIdIyn900VTC0gv9ZTNDYhss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}