SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be894bbf808ea7ba83ad12ddba762af2a79a5185eff79fbcb7d705851b0c6ca8' 
  AND token = 'bPhSQMpb2AI2iYpbos9wRKRXOmZYqSrmJDt5wBgCEis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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