SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b80a6519e157ae2c0abf51517a04ad555e20057d174608a4d14698baf43f94b' 
  AND token = '32sbFWX+O2cB8VAUACcvTs6rRjt0VxLC1Fy8EbYAsGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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