SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d9f0693e50d4197b1ed0921f573d21a4ffd735575f3bf9ca8a31d7ebeb0a810' 
  AND token = 'a2hPYzVmdznZPbs3CLdWn7m2i+U9zKyH4lrv7HicM4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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