SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd57b1e732b952ddb6f7332a19b94f1e7455e9f684dfbb4a38296da73b13057e8' 
  AND token = 'mWsQiG07tqOKZlhFn9a2i5e0g/SzTgxJVdmMm8d5hmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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