SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b197beba75e4e6027bd2eb466cd5bbc72c075d323c54de6fbe72c67f8f03479' 
  AND token = '/axpxaSqSQnbcpupU3QJHqNGPmSGutKetVZrbepU2Cc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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