SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '864333f4388f4584db221e6f98ca63f53e37a5249369c103fd711e84902a08b8' 
  AND token = 'a1rHDOMbpJW5AAntKxbdR5WBZqAHVSk8NnGubeAcz8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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