SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad4acbd56e1255f3c17cb3f58e98d5cd329118b79d3f415997881d9fc47210b1' 
  AND token = '0Fp+b3nd8jJhfOqbtHxJ12zIXS0vVYahu4bJOGyLNss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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