SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '315c128fa8e321d3cda02c195c8fe0e91f1102f553a98c4b8d4fcc16eb2fab7f' 
  AND token = 'wbazfHFY/81cV5GsUxU+9jUaK8gVk5GZgOuPIkaDKPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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