SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c55065dcf2298334a307ac101ba59fc93d95f8eaec9f6f82a866c491f7ce14e' 
  AND token = 'UMBTPVomZljc8Xri0cXI+XKHjxS5i+gyGUsXbjJi/qU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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