SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1207dbf5e0d01e556e7a7950c0fe5626765215cacaaebb9c9bd2206005ed7b8c' 
  AND token = 'yZgULFk+ASaHI9JPyWQYDQhd69FWngRSbZJqJ87er94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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