SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dda852d669af10bf8565b80963397c4c3ec732653a2ec157a21326897fdbaa1' 
  AND token = 'D/CZh3qg0PlgiPwuKuARZ36X6K6aE/2W8E7CL0oNJDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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