SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a272d04aeab8f7f55ff756547392bb0fd18b59b737b152cf85ee3b7b29901b34' 
  AND token = 'U9Jg8kLggR+55pLokX8/74Bv0Vwt5EgmRILROrzePxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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