SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '584daadaf7d90862d0f3264c2f030cac42d0c521842b5b5de85bd9a69b35c317' 
  AND token = 'AawcP3GH74rwVK3vC8tmH1ZtPhmJtZcljW2Up9eDwDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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