SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4590686ab2abfdb43caaeed2fdf22090e68ea17bd5b7f68ec7c07863e703a4b4' 
  AND token = 'NGNGOwbszJgZWGXHdWg1Z7RP0v3daxRHkpWbD2OFApQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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