SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '826207a1a7f9b2456c50b94d70b914798c2f8e7eaddd072b07a4bbfcbd95ce00' 
  AND token = '6i2UduGm/F2BhxzBbB1G8QhjrGnWGUF6XHZyPibuP7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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