SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e4ebe348b41aca0600df79b76b7efe7c9fbafec7fc2af8916e4c7273f1c384e' 
  AND token = 'Lg9nZqfq05pihu5UuY3pho7l+H4oQMmhvUJGY3Plz98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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