SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'aaa931d4901498e096f6c06204c8a2a4456ecee186bb8ee3a1f56bd82cd82d2d' 
  AND token = '3B8RNi5Y0s/y2sj2mGxRAmA0GTFTft7QnLWhQ2nrrEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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