SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d14947b7b75f9772308c80b32b926002216ecd2c9e94624ccfc044f43df4015' 
  AND token = 'GjVDLWv/nq+g2hm8EiYVXlJbZSXzAN70MLHdJ5DGP3M=' 
  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"
    }
  }
}