SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11da98d4358cfdd69f58cf47bff6a5f8a706beaadb6fce179c2a4df518a385a5' 
  AND token = 'lL4UZowgES47AbkK/xo4mkLOCM4VRrXofRnugn/fyGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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