SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0154921f7064e032c64ae2d3a5f893de91d5f90d45025be7c7a6439f609faee2' 
  AND token = 'WPupaw1wOHl+Q5xbhO58VLehv826zNBd8xn2xmzzVKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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