SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e800c3e5e55feb6bfc42861634bcac63a7310540e5cae2cdcd604689f9138b1d' 
  AND token = 'X4LtycBaURk5c+W+QRlFnpytv+dA9kfO1JKBEB5LOZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}