SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0f4418193ba938124cec2e62b99ff5769f9ca6489b828d417c46f1f56e98fb3' 
  AND token = 'Lv6EQ/UgP+uLDECDAhbIYwc+7b0WmpwrxnjcUgHf5R4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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