SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc071df7f9c52b5faf1fc3ea708882f2749ebf7e88f0680b15a89e0c0491a64c' 
  AND token = '9EKEifEbXBG3mEvkZLbp5wprjKcv5P+GX3zqQpCSCjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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