SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ac9c089c61240bf289f42b6812721ac5c9bb0a203f235c81ee14a48f66b5d0ce' 
  AND token = 'C6HJRFqJFyAFAru9/S+ndBTE7guCEygq6kZlnbg/rzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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