SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56196df1abcf666ad653c9508e34627f9a474b5bbd75a2aec3c533cbb9eeafbf' 
  AND token = 'Uo3T41PqtRS2jKgw61hBjCc8IBonbdJG4szF3WPV6vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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