SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c0647b0aa099c6ba549cfb9ebf8f6391c06560baefe326c838771861eea091d' 
  AND token = 'LHeazcack7YIUTV5tBT8OPqAN3a2PlNXArCU6MEocKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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