SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '021f5fde1b43d5358abe8426a73530f516f1e87dd71560ad8907c5ba637e4069' 
  AND token = 'IW/eLEZomh/CAuFyX3mCCBPW2Q5lHDhyxzDQ8zROZCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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