SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '316d27472617eab85f8214745bf23d57e5379d721ce4ef2f0e27f686ac85cf19' 
  AND token = 'ekIn5tjxQqda8GFyDmOCk5gaH/kcdfl1rIinBZQnR+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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