SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76d1070d995829a3fbdaac3f97a8af4e7c7b3b22954ce9f43603773ceddd4acc' 
  AND token = '9Tzq1Pm+VPYrx+auyWl8WKP8+gZWjJxozgXL/9O3as4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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