SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4215e2c048e753b42642978d34457b73d2ad677de50ea15fe5f011faac19a04f' 
  AND token = 'YV/uV8Ap/g+gwVhxf0YS7LlzwJYCiiGpPwXMc0TrdJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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