SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ea3df6fee0ba6e0f8eb0a46fe016dc7e3f6a5695afe8166147c0aa53842ea8a' 
  AND token = 'AVR2qhvpiu3LibwkeSIuxxdRJmAF0cC4y6TB8p+EwHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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