SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ca152f3cf275596520bd30187fc985f1f4a25e07138d51efd388ae66f14e1de' 
  AND token = '1OOJ5SUIAowOaYNyKRbpxxKmHK6UbLUGB4osrS9qwFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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