SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f837793f639ca1aa94d5f6cc05415fc976d82e0b145d6ce30fcc70878336ef3' 
  AND token = 'nh2zMK2VDeE+Jq/fzvXPcGbLJnXHj5cdmX2vckCFo2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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