SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a69ddc43094206120fc569c145b8f3253275cf5227ea94bd2a05c072b60dcef7' 
  AND token = 'n2IX4NuU58t28UKRL5Wirnjm51Mjquilwn+tqahp5LU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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