SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c49e2062324a37bca6e3e4db58397bfb4470604598a586dade0ed633e76932f3' 
  AND token = 'tJuXwjhow6LyjvGERh0OglcsEYzK0pxiKGgiP3pDYEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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