SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6679f2dcffbd9944b595bd58ee5c4c1434c1781c31b5206a583f88864f3e9fcd' 
  AND token = 't4Nkuktnstj4R4A6FEBG2sBphrqYkZN5kuPUpIVOHUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}