SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e507fe1d7745627fba65dea921b774ffcd3a82b738e6ee069b8b462eeb7979f7' 
  AND token = 'PJHuGpBWZdljEv8bD3ZtV4ODeZIIFY/16z7TPhrjhFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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