SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e125bef4a20393536d0528d6207384dc976616a65f76c9923244090c8b017d8e' 
  AND token = 'WVfN6Af0LPU2NQBHhsFQZ1cVBKheDdkd0XNWzwUWolc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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