SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ded2b918f00ac63f8253024051b6eef01cb30fc4604e11f5c20340c82f63259b' 
  AND token = 'NO7mYRSeRfr9rlrBV+RHdvnD9I0J5adP3nAoOrlZQhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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