SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b12ab20515791fc3a3486a0769b9e4d9c098102f00cb1f315c58704abdec6965' 
  AND token = '1IHwipCNSh0kq7dQO4GArvYTw/IHdJ5G79z1JkIvIrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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